Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. Consumers have become dependent upon wireless communication devices such as cellular telephones, personal digital assistants (PDAs), laptop computers, and the like. Consumers have come to expect reliable service, expanded areas of coverage, and increased functionality.
A wireless communication device may be referred to as user equipment, a mobile station, a subscriber station, an access terminal, a remote station, a user terminal, a terminal, a subscriber unit, etc. The term “user equipment” (UE) will be used herein.
A wireless communication system may provide communication for a number of cells, each of which may be serviced by a Node B. A Node B may be a fixed station that communicates with UEs. A Node B may alternatively be referred to as a base station, an access point, or some other terminology. The term “Node B” (NB) will be used herein.
UEs may communicate with one or more Node Bs via transmissions on the uplink and the downlink. The uplink (or reverse link) refers to the communication link from the UEs to the Node B, and the downlink (or forward link) refers to the communication link from the Node B to the UEs. A wireless communication system may simultaneously support communication for multiple UEs.
Wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, clustered SC-FDMA, NxSC-FDMA (a natural number N times single carrier frequency division multiple access), and orthogonal frequency division multiple access (OFDMA) systems.
The 3rd Generation Partnership Project, also referred to as “3GPP,” is a collaboration agreement that aims to define globally applicable Technical Specifications and Technical Reports for 3rd Generation Systems. 3GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. The 3GPP may define specifications for the next generation mobile networks, systems, and devices. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN).